Various types of solar cells converting the energy of sunlight directly into electric energy are now put into practical use. Particularly, development of a thin-film solar cell employing a thin film of amorphous silicon or microcrystalline silicon is now in progress in view of allowing fabrication at low cost by virtue of the low-temperature process and area increase.
FIG. 10 is a schematic sectional view of an example of a conventional thin-film solar cell disclosed in PTL 1 (WO2008/152865). A thin-film solar cell 100 has a configuration in which a transparent conductor film 102, a photoelectric conversion layer 103 constituted of an amorphous silicon thin film, and a back electrode layer 104 are stacked in the cited order on a translucent insulation substrate 101.
Transparent conductor film 102 is separated into strips by separation lines 105, 105a filled with photoelectric conversion layer 103. Photoelectric conversion layer 103 and back electrode layer 104 are separated into strips by a separation line 107. Then, through a contact line 106 where photoelectric conversion layer 103 is removed by patterning using a laser beam or the like, adjacent cells 110 are electrically connected in series to constitute a cell string 111.
A bus bar 109 is provided at each end of cell string 111 in the direction of series connection of cell 110, at the surface of back electrode layer 104 with conductive tape 108 therebetween.
A method of fabricating conventional thin-film solar cell 100 shown in FIG. 10 will be described hereinafter. First, transparent conductor film 102 is stacked on translucent insulation substrate 101. Then, by laser scribing, transparent conductor film 102 is removed in strips to form separation lines 105, 105a. 
By plasma CVD, a p layer, an i layer, and an n layer formed of an amorphous silicon thin film are sequentially stacked so as to cover transparent conductor film 102 separated in strips by separation lines 105, 105a to constitute photoelectric conversion layer 103. Then, photoelectric conversion layer 103 is removed in strips by laser scribing to form contact line 106.
Next, back electrode layer 104 is stacked so as to cover photoelectric conversion layer 103. Accordingly, contact line 106 is filled with back electrode layer 104.
Then, by laser scribing, separation line 107 separating photoelectric conversion layer 103 and back electrode layer 104 is formed. Accordingly, on translucent insulation substrate 101, a cell string 111 having a plurality of cells 110 connected electrically in series is formed, each cell including a transparent conductor film 102, a photoelectric conversion layer 103, and a back electrode layer 104 stacked in the cited order. The electrical connection of cells 110 is effected by bringing transparent conductor film 102 of one of adjacent cells 110 in contact with back electrode layer 104 of the other of adjacent cells 110 through contact line 106.
Then, following the attachment of a conductive tape 108 at each end of the surface of back electrode layer 104 in the direction of cells 110 in series connection, a bus bar 109 is provided. Thus, a conventional thin-film solar cell 100 is produced.